Well, don't laugh too hard (although the video is silly, it looks like they're having great fun) the first part with the sanding block has value. Many machine shops have long since stopped using a cutting tool to machine heads and instead use a belt sander type machine. I've used a modified technique by hand with a block of wood (2x4 cut as long as the head is wide) -- wrap it with a wet/dry cloth backed sheet (the black ones-medium grit) and lubricate it liberally with ATF. I almost fell out of my chair watching the clip when the fellow on the left was handed a beer--I thought he was going to use it as a lubricant. This technique will clean up minor imperfections in the head surface.